WCDMA device and method for discontinuous reception for power saving in idle mode and flexible monitoring of neighboring cells

ABSTRACT

A WCDMA enabled user equipment device configured to have functions collectively or selectively idle to conserve power. A discontinuous receiver is used to detect and read network messages and report the messages to the computer within the WCDMA enabled user equipment device. The computer then activates functions previously powered down to receive incoming messages for the user of the device. The discontinuous receiver is also used when the device is active to read network messages, freeing a modem of the device to operate on user messaging; and therefore, enhancing user related performance.

This is a divisional application of U.S. Ser. No. 11/280,524, filed onNov. 16, 2005, which is herein incorporated by reference in itsentirety, and assigned to a common assignee.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention is related to mobile phones and in particularpower saving for mobile phones comprising wideband code divisionmultiple access.

2. Description of Related Art

WCDMA (Wideband Code Division Multiple Access) has become a thirdgeneration standard for mobile communications. The WCDMA replaces theGSM (Global System for Mobile Communications) a second generationstandard, which is oriented to voice communications with limited datacapability. The demand by users for not only voice communications butalso Web browsing, downloading E-mail, and sending pictures has placed ademand for higher data rate capability. The WCDMA standard provides aspectrum with a 5 MHz carrier, which provides approximately a fiftytimes higher data rate than the second generation GSM technology. Alongwith the higher data rate capability come the need to use more power andin turn the need to have power savings to moderate the demand on thebattery life of a mobile or cellular phone.

There are numerous power saving techniques that have been developed forfirst and second generation mobile phones. In U.S. Pat. No. 6,944,210 B1(Michel et al.) a method is directed to receiving or transmittingmessages wherein the use of spreading codes for CDMA signals providesfor power saving measures. U.S. Pat. No. 6,741,836 B2 (Lee et al.) isdirected to a dual mode Bluetooth/wireless mobile unit wherein a sleepmode a wakeup time is rescheduled to synchronize with any upcoming idlemode wireless wakeup time that will precede the Bluetooth wakeup time.U.S. Pat. No. 6,690,652 B1 (Sadri) is directed to a WCDMA system whichincludes a base station transmitter and a pilot channel that transmitscontrol signals between the base station and the mobile station.

In U.S. Pat. No. 6,639,905 B1 (Muller et al.) a transmitter is directedto controlling at least one receiver by intermittently transmittinggroups of messages and increasing the efficiency of transmitted controlmessages without markedly increasing power consumption of transceiversin the radio frequency network. U.S. Pat. No. 6,526,295 B1 (Shull) isdirected to a power saving method comprising the delay of the turning onof a local oscillator in a mobile phone while the processor of themobile phone sorts through a previously received neighbor list andincludes a method for generating compensation factors for use in powersavings. U.S. Pat. No. 6,356,595 (Czaja et al.) is directed to a methodthat affords low error rate and allows for improved power conservationby a mobile station. U.S. Pat. No. 6,356,538 B1 (Li) is directed to asystem for operating a wireless communications device in a manner thatsignificantly reduces power consumption of the device.

In U.S. Pat. No. 6,219,564 (Grayson et al.) a digital mobilecommunication station is directed to a high frequency time base circuitthat shuts down for a predetermined period for power saving purposes.U.S. Pat. No. 6,125,260 (Wiedeman et al.) is directed to a radiofrequency map that can be used to reallocate frequency channels ofoperation and resulting in power savings in a mobile phone whilemaintaining a suitable signal-to-noise ratio. U.S. Pat. No. 6,041,241(Willey) is directed to an apparatus and method for balancing powersavings and call setup time for a wireless communications device. U.S.Pat. No. 5,983,116 (Nash et al.) is directed to a radio telephone havingan analog key signal output for power conservation. U.S. Pat. No.5,905,943 (Wiedman et al) is directed to the use of a radio frequencymap to reallocate frequency channels resulting power savings in a mobilephone. In U.S. Pat. No. 5,890,005 (Lindholm) a method is directed toreducing power consumption in an electronic system such as a wireless orcellular phone. U.S. Pat. No. 5,752,201 (Kivari) is directed to acellular communication device that includes a controller which placesthe user terminal in a powered down state for a period of time dependingupon the number of filler messages.

In U.S. Pat. No. 5,715,278 (Croft et al.) a method is directed to anapparatus for reducing standby power in a mobile phone whilesimultaneously increasing the probability of receiving the intendedmessage. U.S. Pat. No. 5,701,329 (Croft et al.) is directed to a powersaving standby mode that can be used in mobile radio stations operatingin current networks and improving the intended message reception. InU.S. Pat. No. 5,570,369 (Jokinen) a method is directed to reducing powerconsumption in a mobile phone system wherein a broadcasted message isreconstructed from a partial signal from a base station. U.S. Pat. No.5,568,513 (Croft et al.) is directed to a power saving standby mode thatcan be used in mobile radio stations using a CRC check to determine whento be on the power saving mode. U.S. Pat. No. 5,291,542 (Kivari et al.)is directed to a circuit arrangement for a mobile phone comprising amicroprocessor that is responsive to a clock signal, which leads toreduced power consumption.

In FIG. 1 is shown a block diagram of a WCDMA device of prior art. An RFunit 10 couples signals to and from a modem unit 11. A search function12 is contained within the modem unit 11 to search the spread of anincoming base band data over approximately a 5 MHz band. A hostprocessor 13 sets up and controls the modem and RF units. Data, such asInternet, text and pictures, received by the modem 11 is coupled to thehost computer 13 for display on a screen of a mobile phone 14. Data,such as internet text and pictures, generated by the mobile phone 14 arecoupled to the modem for transmission by the RF unit. A power managementscheme is needed for the mobile phone 14 to allow the reception ofsignals while at the same time preserving battery power life. The modem11 amongst other features provide a heavy drain of power from thebatteries of the mobile phone.

SUMMARY OF THE INVENTION

It is an objective of the present invention to minimize use of powersupplied by batteries through conservation techniques in a WCDMA device,where the WCDMA device is enabled user equipment comprising a mobilephone device, a PDA (personal data assistant), and PCI (peripheralcomponent interconnect) cards.

It is also an objective of the present invention to use discontinuousreception to minimize the time that functions of a WCDMA device areactive to receive signals and in turn reduce the demand for power.

It is also further an objective of the present invention to use a pagingoccasion timed by internal counters of a WCDMA device to wake upportions of the WCDMA device to look for incoming messages.

It is still an objective of the present invention to configure functionsof a WCDMA device to allow major portions of the WCDMA device to be in asleep or partial active mode while monitoring signaling activity or byperiodically providing a paging occasion to detect possible incomingmessages and when detected, activating functions sleeping or in apartial active state to receive a message.

It is still further an objective of the present invention to monitornetwork messaging without the use of a modem of the WCDMA device andallowing the modem and other major functions of the WCDMA device to bepowered down to conserve power.

It is still yet an objective of the present invention to monitor andread network messages without the use of the modem of the WCDMA deviceto enhance the performance of user messaging in the WCDMA device.

In the present invention a DRX (Discontinuous Receiver) unit is used todetect network messages, for example PICH (paging indicator channel)signals, and when the modem DSP (digital signal processor) is asleep,demodulate S-CCPCH (secondary common control physical channel) signals.The use of the DRX allows major functions of the WCDMA device, which isenabled user equipment comprising a mobile phone, a PDA and PCI cards,to be powered down in a sleep mode to conserve power. The DRX alsoenhances performance of the WCDMA device in active state by readingnetwork messages, free the modem from reading these messages andenhancing the performance of the WCDMA device on user messaging. Afterdemodulating S-CCPCH signals the DRX wakes up the host computercontained within the WCDMA device and hands over a paging message to thehost computer.

The DRX contains a search engine, similar to that contained within themodem function of the WCDMA device and is used when the modem DSP(digital signal processor) of the WCDMA device is asleep. The searchengine detects portions of an incoming signal that has been spread overa several mega hertz of signal bandwidth, which has been done to improvemessaging bandwidth to accommodate the Internet and large data messagingsuch as transmission of pictures.

In the present invention the DRX unit monitors signals (digital IQ data)from the RFTRX (radio frequency transceiver) unit. The digital IQ datais two data streams, I=ln phase data modulated to the cosine componentof the signal carrier and Q=Quadrature data modulated to the sinecomponent of the signal carrier. The DRX reports signal events to thehost processor of the WCDMA device and is set up by the host processorto detect various network signals that are broadcast by a base stationof the network. The various modes disclosed in the present invention areall directed to saving power drain on the batteries of the WCDMA deviceand extending the time between charging of the batteries.

The DRX unit is also used to monitor cells that are near the cell withinwhich a WCDMA device operates. To perform cell monitoring, theenvironment is monitored to determine which cells are within reach bythe WCDMA device signals using a search function that is located in theDRX unit as well as in the modem of the WCDMA device. Discontinuousactivities of the WCDMA device to conserve the use of battery powernecessitates the use of “snapshots” of the environment which is similarto monitor of the paging channel but does not require the demodulationof a PICH signal.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention will be described with reference to the accompanyingdrawings, wherein:

FIG. 1 is a block diagram of a WCDMA mobile phone of prior art;

FIG. 2 is a block diagram of a WCDMA device of the present invention;

FIG. 3A is a block diagram of the DRX unit used in the first embodimentof the present invention for discontinuous reception of a PICH signal inidle mode;

FIG. 3B is a block diagram of the DRX unit used in the second embodimentof the present invention for autonomous discontinuous reception ofnetwork signals in idle mode;

FIG. 3C is a block diagram of the DRX unit used in the third and fourthembodiment of the present invention for discontinuous reception in idlemode managed by a host processor;

FIG. 3D is a block diagram of the DRX used in the fifth embodiment ofthe present invention unit for cell monitoring in active mode;

FIG. 4 is a flow diagram of a method of the present invention in an idlemode using a modem DSP search engine;

FIG. 5 is a flow diagram of a method of the present invention in idlemode using the DRX to detect an incoming signal and wakes up appropriatefunctions within the WCDMA device.

FIG. 6 is a flow diagram of a method of the present invention in an idlemode managed by the host computer;

FIG. 7 is a flow diagram of a method of the present invention for cellmonitoring in idle mode; and

FIG. 8 is a flow diagram of a method of the present invention for cellmonitoring in a connected mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 2 is shown a block diagram of a WCDMA device 20 of the presentinvention, where the WCDMA device is enabled user equipment comprising amobile phone, a PDA and PCI cards. A host processor 21 is coupled to amodem unit 22, a DRX (discontinuous receiver) unit 23 and an RFTRX (RFtransmit and receive) unit 24. The RFTRX unit 24 is coupled to the modemunit 22 and the DRX unit 23 providing digital IQ data to the modem andthe DRX unit. The IQ data provides two data streams “I” and “Q” whereI=“ln phase” which is modulated to the cosine component of carriersignal and Q=“Quadrature phase”, which is modulated to the sinecomponent of the carrier signal. Contained within the modem unit 25 is asearch function 25 that is used to detect portions of an incoming signalthat has been spread over a several mega hertz of signal bandwidth toimprove messaging bandwidth to accommodate the Internet and large datamessaging such as transmission of pictures. The host processor 21 andthe modem unit 22 are preferred to be integrated together on the samesemiconductor device 26; although, separate devices can be used for thehost processor and the modem unit. In like manner the RFTRX unit 24 andthe DRX unit 23 are preferred to be integrated together on the samesemiconductor device 27; although the RFTRX unit and the DRX unit can belocated on separate semiconductor devices.

Continuing to refer to FIG. 2, the host processor 21 controls andconfigures the peripheral units comprising the modem unit 22, the RFTRXunit 24 and the DRX unit 23 to perform in various power saving modes,where the host processor and the peripheral units can be in an activestate or various low power standby modes in an idle state, comprising asleep state and a partially active state. When in a sleep state aparticular function is powered down and provides no functional response.In the partially active state a particular function is partially powereddown leaving critical elements active to perform critical operations ofreceiving and sensing incoming signals and reporting results to otherfunctional units, for example the host processor.

Continuing to refer to FIG. 2, in a first embodiment of the presentinvention a discontinuous reception of the PICH (paging indicatorchannel) signals in idle mode is performed. The WCDMA device 20 ispowered up, and the host processor and the peripheral units comprisingthe RFTRX 24, the modem 22 and the DRX 23 are turned on to obtain systeminformation and register with the cellular network. The RFTRX 24, modem22 and the DRX 23 are set into an idle mode in which each of theperipheral units return to a partial active state. A paging occasioncreated by internal timers within the host processor 21 activates theperipheral units by activating the RFTRX 24, modem, 22 and the DRX 23. Apaging occasion defines the radio frame ID (identification) at which thePaging Indicator Channel (PICH) carries the Paging Indicator Bit for theWCDMA device of interest. The PICH is the paging indicator channel,which is a common channel that carries the paging indicator bits for allWCDMA devices in a cell. The timing of the paging indicator bit for aspecific WCDMA device is given by the paging occasion that defines theradio frame ID, and the ID of the paging indicator bit defines therelative timing within a radio frame. A Paging Indicator Bit is used tonotify a specific WCDMA device or a group of WCDMA devices about thetransmission of a paging message by the network for the WCDMA device orthe group of WCDMA devices.

Continuing to refer to FIG. 2, the search function 25 within the modem22 reports to the host processor 21 the detection of portions of anincoming message that has been spread over a several mega hertz ofsignal bandwidth. The host processor 21 configures the DRX 23 to detectPICH (paging indicator channel) signals and in turn the DRX notifies thehost processor of a paging bit, whereupon the host processor activates(wakes up) the modem to demodulate S-CCPCH (secondary common controlphysical channel) signals and report the paging message to the hostcomputer. The S-CCPCH carries the paging messages transmitted by thenetwork. Upon detection of a positive Paging Indicator received on thePICH, the WCDMA device receives the associated S-CCPCH frame thatcarries a paging message.

Continuing to refer to FIG. 2, in the first embodiment the DRX unit 23does not require an internal search engine since the host processor 21provides synchronization of the DRX unit based on the modem searchreport from the search function 25. The host processor is in a low powerstandby mode (partially active in terms of power consumption) to providecontrol to the modem 22 and the DRX unit 23. The RFTRX 24, DRX 23 andthe modem 22 are partially active in terms of duty cycle and becomefully active during a paging occasion.

Continuing to refer to FIG. 2, in a second embodiment of the presentinvention the functions of a WCDMA device are in idle mode where the DRXunit 23 operates autonomously and contains internal timing and a searchengine to perform a search function to perform the detection of incomingnetwork messages. The WCDMA device is powered up, activating the hostprocessor 21, the RFTRX unit 24, the DRX unit 23 and the modem 22. Thehost processor configures the DRX unit 23 to detect PICH and S-CCPCHsignals.

Continuing to refer to FIG. 2, in a third embodiment of the presentinvention a discontinuous reception of a PICH signal is performed in anidle mode. The WCDMA device 20 is powered up and the host processor 21,the RFTRX unit 24, the DRX unit 23 and the modem 22 are active to obtainsystem information and register with the cellular network. The RFTRXunit 24 and the DRX unit 23 enter a partial active mode and the modem 22goes to a sleep state after registration is completed. Upon a pagingoccasion the host processor 21 awakens the RFTRX unit 24 and the DRXunit 23. The RFTRX unit and the DRX unit are in partially active stateand are only fully active during the paging occasion.

Continuing to refer to FIG. 2, in a fourth embodiment of the presentinvention the WCDMA device 20 performs cell monitoring in an idle mode.The WCDMA device 20 is powered up and the host processor 21, the RFTRXunit 24, the DRX unit 23 and the modem 22 are active to obtain systeminformation and the register with the cellular network. The RFTRX unit24 and the DRX unit 23 enter a partial active mode and the modem 22 goesback to a sleep state after registration is completed. The cellmonitoring is managed by the software running on the host processor. Thehost processor uses an internal timer by which the software triggersmonitoring events. The frequency of the cell monitoring depends on thesoftware that is running on the host processor and the environment inwhich the WCDMA device is moving as the WCDMA device changes location.

Continuing to refer to FIG. 2, in a fifth embodiment of the presentinvention the WCDMA device 20 performs cell monitoring in a connectedmode, for example talking on a WCDMA mobile phone. The WCDMA device 20is powered up and the host processor 21, the RFTRX unit 24 and the modem22 are active. The DRX unit 23 is partially active and does not read thePICH signal since the mobile phone 20 is already active. The hostprocessor 21 manages the peripheral units (RFTRX 24, DRX 23 and themodem 22). In the advent of a cell monitoring event the host processor21 activates the DRX unit 23 to monitor candidate cells. Candidate cellsare those cells to which the WCDMA device can perform a handover tomaintain adequate signal strength. If the WCDMA device keeps changingits location, the signal from one or more active cell that are currentlyexchanging user data with the WCDMA device will eventually get weak. Inorder to maintain connection with the network (e.g. to avoid dropping acall) the WCDMA device constantly needs to promote previously identifiedcandidate cells (upon negotiation with the network) into its set ofactive cells. If required the host processor 21 configures the RFTRXunit 24 to receive an active carrier while monitoring other carriers ina compressed mode. The overall WCDMA receive bandwidth (e.g. 60 MHzwide) is divided into segments of 5 MHz (e.g. 12 segments). One segmentis called carrier. A network operator may transmit on one or multiplecarriers. The active carrier is a carrier selected by the network toexchange data with the mobile phone. The control software running on thehost processor negotiates with the network which carrier to select asthe active carrier.

Monitoring other carriers is required for the same reason as monitoringother cells in order to maintain connection to the network when changingthe location. Compressed mode is required if carriers other than the onecurrently used for exchange of user data (active carrier) is subject tomonitoring. During compressed mode the network interrupts transmissionof data at the active carrier for a defined time (compressed gap) toallow the WCDMA device to tune its receiver to another carrier formeasurements. This process is initiated upon signaling from the network.

The host processor 21 then configures the DRX unit 23 to search onP-CPICH (primary common pilot indicator) and complements the overallsearch capacity of the WCDMA device 20 in connected mode using a searchengine within the DRX unit. The P-CPICH is used by the network fortransmission of a predefined pilot signal (pilot bit sequence know bythe WCDMA device a priori) to facilitate synchronization of the WCDMAdevice receiver. Since the WCDMA device knows exactly what bit sequenceto expect on the PCPICH, the WCDMA device can correlate the receivedsignal with the expected sequence and thus determine the exact timing ofthe received signal (including detection of resolvable propagationpaths, which look like delayed versions of the transmitted bitsequence).

In FIG. 3A is a block diagram of the DRX unit 23 (FIG. 2) of the firstembodiment of the present invention (where 23A is the version of the DRXused of the first embodiment). In the first embodiment the DRX unit 23Adoes not require an internal search engine since the host processor 21provides synchronization of the DRX unit based on the modem searchreport from the search function 25. The host processor is in a low powerstandby mode (partially active in terms of power consumption) to providecontrol to the modem 22 and the DRX unit 23A. The RFTRX 24, DRX 23A andthe modem 22 are partially active in terms of duty cycle and becomefully active during a paging occasion.

Shown in FIG. 3A, the receiver management software 31 registers theinterface rake 32 and the interface code generator 34 with the mobilenetwork after which the DRX unit 23A enters an idle mode waiting for apage occasion and the receipt of a paging bit on the PICH channel fromthe digital I/Q data. When a paging bit is received by the rake receiver33, the paging bit is coupled to the receiver management software 31 inthe host computer 21. A system clock is coupled to a timing unit 36within the DRX 23A, and the timing unit 36 distributes timinginformation to the rake receiver 33 and the scrambling andchannelization code generator 35.

The scrambling and channelization code generator 35 is connected to therake receiver 33 in the DRX 23A to unscramble and un-spread a WCDMAsignal, which for bandwidth and noise purposes has been spread by a basestation over a wide band of signal frequencies. A spreading code is usedto spread a narrow band user signal over the WCDMA bandwidth where everyphysical channel transmitted by a base station uses a differentspreading code. All spreading codes used by a base station are mutuallyorthogonal to minimize interference between the physical channels. Oncea narrow band user signal has been spread, the signal is then multipliedwith a scrambling code, where different base stations uses differentscrambling code to minimize interference between different signals fromdifferent base stations. To demodulate a received signal a WCDMA devicemust unscramble and un-spread the wideband transmission from the basestation into a narrow band signal.

In FIG. 3B is shown a second embodiment of the present invention wherethe functions of a WCDMA device are in idle mode and where the DRX unit23B operates autonomously and contains internal timing and a searchengine to perform a search function to detect incoming network messages.The WCDMA device is powered up, activating the host processor 21, theRFTRX unit 24, the DRX unit 23B and the modem 22. The host processorconfigures the DRX unit 23B to detect PICH and S-CCPCH signals, where23B is the version of the DRX used in the second embodiment.

Continuing to refer to FIG. 3B, the host processor 21, the RFTRX unit 24enters a partial active mode and the modem 22 enters a sleep mode toconserve power. When the DRX 23B detects a paging occasion by detectinga PICH signal, the DRX unit 23B awakens the RFTRX unit 24. If there areS-CCPCH signals, the DRX unit 23B demodulates the S-CCPCH signals, wakesup the host processor 21 and hands over to the host processor the pagingmessage. The DRX 23B contains a search engine and capability to processthe S-CCPCH signals as well as the capability to handle PICH and S-CCPCHsignal autonomously. The DSP (digital signal processor) in the modem 22containing the search function 25 is only required if demodulation ofchannels other than the PICH and the S-CCPCH are required and remainsasleep until that need arises. The host processor 21 may need to remainpartially active to manage tasks other than paging events during idlemode caused by complexity of the S-CCPCH signal processing such asmulti-rate rake that occurs at a data rate different than PICH signalsand a secondary channel that uses channel encoding.

The rake receiver is the classical receiver in CDMA (Code DivisionMultiple Access). Each “finger” of the rake receiver is assigned to oneresolvable propagation path of the signal. The propagation path is aversion of the transmitted signal associated with a certain delay andattenuation. In CDMA the narrow band user signal is spread over arelatively large bandwidth. The employed spreading factor describes thebandwidth ratio after and before spreading of the user signal.

Some common channels in WCDMA use a fixed spreading factor (e.g. thePICH). The corresponding rake receiver uses de-spreading at a fixedrate. The S-CCPCH features variable spreading factors, thus thecorresponding rake receiver needs to be capable of performingde-spreading at multiple spreading factors (multi-rate rake). Somechannels (typically the ones that carry only layer 1 information e.g.PICH) carry un-coded information. Other channels (typically the onesthat carry higher layer data and control information e.g. S-CCPCH) usechannel encoding for improved data protection. To fully process the dataof such a channel an additional receiver module called channel decoderis required.

In FIG. 3B is shown the DRX 23B for the second embodiment of the presentinvention. The host computer 21 containing receiver management software31 is coupled to an internal management unit and timer function 41contained within the DRX 23B. The system clock is also coupled to theinternal management unit and timer 41. The host processor 21 registerswith the mobile phone network the functions of the DRX 23B through thevarious register interfaces, e.g. register interface SCCPCH outer/innerRx 48, Register interface rake 42, register code generator 44 andregister interface searcher 46.

Continuing to refer to FIG. 3B, when the DRX 23B detects a pagingoccasion by detecting a PICH signal, the DRX unit 23B receives a pagingbit from the digital I/Q data coupled to the rake receiver for PICH andS-CCPCH detection 43 and awakens the RFTRX unit 24. If there are S-CCPCHsignals, the S-CCPCH inner/outer receiver function 49 demodulates theS-CCPCH signals, wakes up the host processor 21 and hands over to thehost processor the paging message. The DRX 23B contains a search engine47 (searcher with a bank of correlators) coupled to the digital I/Q datathat allows the DRX 23B to detect various portions of the S-CCPCH signalspread over several mega hertz of signal bandwidth and provides thecapability to process the S-CCPCH signals as well as the capability tohandle PICH and S-CCPCH signal autonomously. Continuing to refer to FIG.3B, a scrambling and channelization code generator 45 is coupled to therake receiver 43 and the searcher 47 to unscramble and un-spread a WCDMAsignal, which for bandwidth and noise purposes has been spread by a basestation over a wide band of signal frequencies. The S-CCPCH inner/outerRx (receiver) 49 converts a signal received from the antenna of a mobilephone into generic data packets. In the WCDMA device receiver the signalcan be divided into “inner receiver” and “outer receiver”. The tasks ofinner receiver in WCDMA mobile system comprise synchronizationunscrambling and un-spreading of the received signal. The tasks of outerreceiver in WCDMA comprise de-multiplexing and channel de-coding.

Referring to FIG. 3C, in a third embodiment of the present invention adiscontinuous reception of a PICH signal is performed in an idle mode.The WCDMA device 20 is powered up and the host processor 21, the RFTRXunit 24, the DRX unit 23C and the modem 22 are active to obtain systeminformation and the register with the cellular network, where 23C is theversion of the DRX used in the third embodiment. The RFTRX unit 24 andthe DRX unit 23C enter a partial active mode and the modem 22 goes to asleep state after registration is completed. Upon a paging occasion thehost processor 21 awakens the RFTRX unit 24 and the DRX unit 23C. TheRFTRX unit and the DRX unit are in partially active state and are onlyfully active during the paging occasion.

Continuing to refer FIG. 3C, the host processor 21 configures the DRXunit 23C to detect PICH signals. When detecting PICH signals the DRX 23Cneeds to know synchronization information, such as the exact timing ofthe paging indicator bit (i.e. ID of the paging indicator bit within therelevant paging occasion), the scrambling code number used by thenetwork, the spreading code number and the timing of propagation pathsobtained from searcher 57. The DRX unit 23C upon detecting a pagingindicator communicates the paging indicator signal, PICH, and a channeldelay profile signal to the host computer 21, whereupon the hostcomputer awakens the modem 22 for reception of an incoming pagingmessage, making use of the synchronization information from the DRX unit23C. The channel delay profile signal provides a snapshot of the searchsignal, resolvable versions, timing reports and power of each signalthat can be resolved. The host processor runs in a power savingpartially active mode, but remains in charge of managing the peripheraldevices and transitions between different modes of the WCDMA device 20.

Continuing to refer to FIG. 3C, the receiver management software 31 inthe host processor 21 is couple to the register interface rake 52,register code generator 54 and register interface searcher 56 toregister the interface rake 53, the scrambling and channelization codegenerator 55, and the searcher 57 with the mobile network after whichthe DRX 23C enters an idle mode waiting for a paging occasion. Theconnection between the receiver management software 31 and the registerinterface rake 52 provides a path by which results from the rakereceiver 53 are communicated to the host processor, and the connectionbetween the receiver management software 31 and the register interfacesearcher 56 provides a path by which searcher 57 communicates searchresults back to the host computer. The scrambling and channelizationcode generator 55 is connected to both the rake receiver 53 and thesearcher 57. Both the rake receiver 53 and the searcher 57 receive inputfrom the digital I/Q data. A timing unit 58 distributes timinginformation based on the system clock to the rake receiver 53, thescrambling and channelization code generator 55 and the searcher 57.

Continuing to refer to FIG. 3C, in the fourth embodiment of the presentinvention the WCDMA device 20 performs cell monitoring in an idle mode.The host processor 21 awakens the DRX unit 23C to perform a cellmonitoring event where the DRX unit 23C monitors the environment ofnearby cells within the mobile phone network using the searcher function57 in the DRX unit. The RFTRX and DRX are active during a pagingoccasion or during cell monitoring, and asleep otherwise. The softwarerunning on the host processor manages cell monitoring, and the hostprocessor uses an internal timer relative to which the software triggerscell monitoring events. The frequency of the cell monitoring depends onthe software that is running on the host processor and the environmentin which the WCDMA device is moving form location to location.

Referring to FIG. 3D, in a fifth embodiment of the present invention theWCDMA device 20 is active and powered up. The host processor 21 hasregistered with the mobile network the scrambling and channelizationcode generator 62 from the receiver management software 21 throughconnections to the register code generator 60, and in like manner thehost processor has registered the searcher 63 with the mobile networkthrough connections with the register interface searcher 61. Thesearcher 63 is coupled to the digital I/Q data provided by the RFTRXunit 24. The system clock is connected to the timing unit 64 fordistribution of timing signals to the scrambling and channelization codegenerator 62 and the searcher 63. After registration the DRX unit 23D isplaced in an idle state

Continuing to refer to FIG. 3D, the host processor 21 awakens the DRXunit 23D to perform a cell monitoring event where the DRX unit monitorsthe environment of nearby cells within the mobile network using thesearcher function 63. The DRX unit is active during cell monitoring, andasleep otherwise. The software running on the host processor managescell monitoring using an internal timer relative to which the softwaretriggers cell monitoring events. The frequency of the cell monitoringdepends on the software that is running on the host processor and theenvironment in which the WCDMA device is moving form location tolocation.

Continuing to refer to FIG. 3D, the WCDMA device 20 is powered up, andthe host processor 21, the RFTRX 24 and the modem 22 are activated intoa full operational state. System information has been collected and theWCDMA device has been registered with a cellular network. The hostprocessor 21 awakens the DRX unit 23D to perform a cell monitoring eventwhere the DRX unit 23D monitors the environment of nearby cells withinthe mobile network using the searcher function 63 in the DRX unit. TheRFTRX unit 24 is configured by the host processor for reception of anactive carrier while monitoring other carriers in a compressed mode. TheDRX unit 23D does not read PICH signals because the WCDMA device ispowered up and in connected mode. The host processor 21 configures theDRX unit 23D to search on a P-CPICH (primary common pilot indicatorchannel) and communicate to the host processor the channel delay powerprofile, which provides a snapshot of the network service. The use ofthe DRX unit 23D in a connected mode allows a searcher 63 within the DRXto perform searches of nearby cells of the mobile network therebyreducing the load on the search function 25 located in the modem 22(FIG. 2). The activity of the DRX unit 23D when the WCDMA device is inactive mode supports the other functions in the WCDMA device in which itcomplements the overall search capacity of the WCDMA device therebyenhancing receiver performance during a connected mode.

In FIG. 4 is shown a flow diagram for the first embodiment of thepresent invention for an idle mode of the WCDMA device 20 where theWCDMA device is initially powered up 100, and all the units of the WCDMAdevice are awakened to obtain system information and to register withthe mobile network 101. The host processor 21 and the peripheral unitscomprising the DRX unit 23, the RFTRX 24 and the modem 22 enter an idlemode are all units placed into a partial active state 102. At the startof a paging occasion the host processor 21 wakes up the DRX 23 the RFTRXunit 24 and the search function 25 of the modem 22 to an active state103. A message is received through the RFTRX unit 104, coupled to themodem, and the modem search engine reports a search result to the hostprocessor 105. The Host processor configures the DRX to detect a PICHsignal 106. The DRX notifies the host processor of a paging bit 107 thatindicates that there is or is not a message, and if the appropriatepaging bit is received the host processor awakens the modem from apartial active state to demodulate an S-CCPCH signal 108. The modem thenreports the paging message to the host computer 109.

In FIG. 5 is shown a flow diagram for the second embodiment of thepresent invention for an idle mode of the WCDMA device 20 fordiscontinuous reception of PICH signals. The WCDMA device is initiallypowered up 120. The host processor 21, the RFTRX 24, the DRX 23 and themodem 22 are awakened 121 into an active state to obtain systeminformation and to register the WCDMA device with a cellular or mobilenetwork. The host processor configures the DRX to autonomously detectPICH and S-CCPCH signals 122. The host processor and the modem enter asleep mode while the DRX remains active and the RFTRX is partiallyactive 123. On a paging occasion the DRX wakes up the host processor,which changes to an active state 124. The DRX detects a PICH signal, andif the proper paging bit is received, the DRX demodulates S-CCPCHsignals 125 and wakes up the host processor to hand over the pagingmessage 126. The modem is only required to power up from the sleep stateif demodulation of other than the PICH and the S-CCPCH signals arerequired.

In FIG. 6 is shown a flow diagram for the third embodiment of thepresent invention for an idle mode of the WCDMA device 20 where the DRX23 has an internal search engine and is managed by the host processor.The WCDMA device is initially powered up 140. The host processor 21, theRFTRX 24, the DRX 23 and the modem 22 are awakened 141 into an activestate to obtain system information and to register the phone with acellular network. The RFTRX, modem and DRX are idled into a sleep mode142. For a paging occasion the host processor wakes up the RFTRX and theDRX units 143, which are placed into a partial active state. The RFTRXand the DRX are only active during and for a short period prior to thepaging occasion to allow for synchronization.

Continuing to refer to FIG. 6, the host computer configures the DRX unitto detect a PICH signal 144 and the DRX couples a paging indicator and achannel delay power profile to the host processor 145. The channel delaypower profile provides a snapshot of the network service, comprisingresolvable versions of signals timing and power of each resolvableversion of the signal. If the appropriate paging indicator is received,the host processor wakes up the modem into an active state to receive apaging message 146. In this embodiment the host processor can be run inpower saving mode, for example partial active mode, but remains incontrol of managing the peripheral units (RFTRX, DRX and modem) and thetransitions between modes.

In FIG. 7 is shown a flow diagram for the fourth embodiment of thepresent invention for cell monitoring in an idle mode of the WCDMAdevice 20. The WCDMA device is initially powered up 160. The hostprocessor 21, the RFTRX 24, the DRX 23 and the modem 22 are awakened 161into an active state to obtain system information and to register theWCDMA device with a cellular network. The RFTRX, DRX and modem areplaced into an idle mode in which these units power down in a sleep mode162. At the occurrence of a cell monitoring event, the host processorwakes up the RFTRX and DRX units 163. The host processor configures theRFTRX unit to receive an active carrier 164, and configures the DRX tosearch for a P-CPICH signal 165 using a search function internal to theDRX unit. The DRX communicates the channel delay power profile to thehost computer 166.

In FIG. 8 is shown a flow diagram for the fifth embodiment of thepresent invention for cell monitoring in a connected mode of the WCDMAdevice 20. The WCDMA device is powered up 180, and the host processor21, the RFTRX 24 and the modem 22 are activated 181 into a fulloperational state. System information has been collected and the WCDMAdevice has been registered with a cellular network. The host processorawakens the DRX unit to perform a cell monitoring event 182 where theDRX monitors the environment of nearby cells within the mobile phonenetwork using a search function in the DRX unit. The RFTRX unit isconfigured by the host processor for reception of a desired carrier 183while monitoring other carriers in a compressed mode. The DRX unit isnot needed to read PICH signals because the WCDMA device is powered upand in connected mode. The host processor configures the DRX unit tosearch on a P-CPICH channel 184 and the DRX communicates to the hostprocessor the channel delay power profile 185, which provides a snapshotof the network service. The use of the DRX unit in a connected modeallows a search function within the DRX to perform searches of nearbycells of the mobile network and thereby reducing the load on the searchfunction located in the modem. The DRX activity when the mobile phone isin active mode supports of the other functions in the WCDMA device inwhich it complements the overall search capacity of the WCDMA device andenhances receiver performance during a connected mode.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade without departing from the spirit and scope of the invention.

1. A discontinuous receiver for a mobile device for discontinuousreception in idle mode managed by a host processor, comprising: themobile device comprising the host processor and the discontinuousreceiver (DRX); the host processor registers with a network coupled tothe mobile device functional units of the DRX comprising a rake receiverand a searcher; the rake receiver upon a paging occasion detects apaging bit and couples the paging bit and a channel delay power profileto the host processor, wherein the channel delay power profile comprisesa snapshot of a network service signal, resolvable versions of thesignal, and timing and power of each resolvable version of the signal;and the searcher provides synchronization information for detection ofthe paging bit.
 2. The discontinuous receiver of claim 1, wherein theDRX further comprises a scrambling and channelization code generator tounscramble and un-spread a PICH (paging indicator channel) messagecontaining the paging bit.
 3. The discontinuous receiver of claim 1,wherein the DRX is in an idle mode prior to issuance of the pagingoccasion by the processor.
 4. The discontinuous receiver of claim 1,wherein the DRX provides cell monitoring when the mobile device is inidle mode.
 5. A method for discontinuous reception of a paging indicatorchannel (PICH) signal in an idle mode in a mobile device, comprising:powering up the mobile device; waking up functional units of the mobiledevice, obtaining system information, and registering with a network;idling an RF unit, a modem, and a discontinuous receiver; waking up theRF unit and the discontinuous receiver by a host processor of the mobiledevice upon a paging occasion; configuring the discontinuous receiver todetect paging indicator signals; communicating a paging indicator and achannel delay power profile from a demodulator to a host processor,wherein the channel delay power profile comprises a snapshot of anetwork service signal, resolvable versions of the signal, and timingand power of each resolvable version of the signal; and waking up amodem to receive a paging message.
 6. The method of claim 5, wherein thefunctional units of the mobile device further comprise the hostprocessor, the RF unit, the discontinuous receiver, and the modem. 7.The method of claim 5, wherein idling the RF unit, discontinuousreceiver, and modem conserves power of the mobile device during a timeof no signal activity.
 8. The method of claim 5, wherein waking up themodem uses synchronization information from the discontinuous receiver.9. The method of claim 5, wherein the host processor runs in a powersaving mode while managing the functional units and transitions betweenmodes.
 10. A method for cell monitoring in an idle mode, comprising:powering up a mobile device; waking up functional units of the mobiledevice, obtaining system information, and registering with a network;idling an RF unit, a modem, and a discontinuous receiver of the mobiledevice; waking up the RF unit and the discontinuous receiver at anoccurrence of a cell monitoring event; configuring the RF unit by a hostprocessor of the mobile device for reception of a signal carrier;configuring the discontinuous receiver by the host processor of themobile device to search for a primary common pilot indicator channel(P-CPICH) signal; and communicating a channel delay power profile to thehost processor by the discontinuous receiver, wherein the channel delaypower profile comprises a snapshot of a network service signal,resolvable versions of the signal, and timing and power of eachresolvable version of the signal.
 11. The method of claim 10, whereinthe functional units of the mobile device further comprise theprocessor, the RF unit, the discontinuous receiver, and the modem. 12.The method of claim 10, wherein idling the RF unit, discontinuousreceiver, and modem conserves power of the mobile device during a timeof no signal activity.
 13. An apparatus for discontinuous reception of apaging indicator channel (PICH) signal in an idle mode, comprising:means for powering up a mobile device; means for waking up functionalunits of the mobile device, means for obtaining system information, andmeans for registering with a network; means for idling an RF unit, amodem, and a discontinuous receiver; means for waking up the RF unit andthe discontinuous receiver by a host processor of the mobile device upona paging occasion; means for configuring the discontinuous receiver todetect paging indicator signals; means for communicating a pagingindicator and a channel delay power profile from a demodulator to a hostprocessor, wherein the channel delay power profile comprises a snapshotof a network service signal, resolvable versions of the signal, andtiming and power of each resolvable version of the signal; and means forwaking up a modem to receive a paging message.
 14. An apparatus for cellmonitoring in an idle mode, comprising: means for powering up a mobiledevice; means for waking up functional units of the mobile device, meansfor obtaining system information, and means for registering with anetwork; means for idling an RF unit, a modem, and a discontinuousreceiver of the mobile device; means for waking up the RF unit and thediscontinuous receiver at an occurrence of a cell monitoring event;means for configuring the RF unit by a host processor of the mobiledevice for reception of a signal carrier; means for configuring thediscontinuous receiver by the host processor of the mobile device tosearch for a primary common pilot indicator channel (P-CPICH) signal;and means for communicating a channel delay power profile to the hostprocessor by the discontinuous receiver, wherein the channel delay powerprofile comprises a snapshot of a network service signal, resolvableversions of the signal, and timing and power of each resolvable versionof the signal.
 15. The method of claim 8, wherein the synchronizationinformation comprises timing of the paging indicator, a scrambling codeused by the network, a spreading code, and timing of propagation paths.